The present invention relates to oil pumps, and more particularly, to a lube oil pump of the type used in internal combustion systems.
One type of lube oil pump used in internal combustion systems is mounted on the engine crank shaft. The body of the pump contains the pump gears or rotors and inlet and outlet ports. A cover plate encloses the pumping mechanism. A low pressure or vacuum inlet conduit extends from an inlet port through the frame into the low pressure, or intake side of the pump chamber, and a high pressure conduit extends from the high pressure, or discharge portion of the pump chamber, to a pump outlet port.
These oil pumps have pressure relief or regulating valves to control engine oil pressure. Such valves generally have a spring-biased piston which uncovers an orifice when overbalanced by oil pressure, creating a variable size relief conduit. Other valving action is commonly provided by placing a spring-biased poppet valve in a bore that leads from a region of high pressure to the inlet. Such a design requires a means for closing and sealing the bore and a means for holding the valve central to the valve seat center line.